Apparatus for making hollow rubber articles.



F. T. ROBERTS. APPARATUS FOR MAKING HOLLOW RUBBER ARTICLES.

APPLICATION'FILED ocT.l|.1915. 4

` Patented Oct. 17,1916.

F. T. ROBERTS. APPARATUS FoR MAKING HoLLow RUBBER ARTICLES.

` APPucATloN man ocT. 11. 191s. 1,201,503. Patented 0@t.17,1916. 3 SHEETS-SHEET 2 GG GGGG GGGG GGGG F. T. ROBERTS. APPARATUS PoR MAKING AloLLow RUBBER ARTICLES.

APPLICATION FILED OCT. II. 1915.

Patented Oct. 17, 1916.

' a SHEETS-SHEET a.

APPARATUS FOR MAKING HOLLOW-RUBBER ARTICLES.

Specification of Letters Patent.

Application led October 11, 1915. Serial No. 55,131.

To all whom-t may concern.'

Be it known that I, FREnTHoMAs Ro- ERTs, a 4citizen of the United States, residling at Trenton, in the county of Mercer and State of New Jersey, have invented a certain new and useful Improvement -in Apparatus for Making Hollow Rubber Articles, of which the following is a full, clear, and exact description, reference being had claims.

to the accompanying drawings.

vMy application No. 51,338, iiledSeptember 18th, 1915, describes and claims aprocess of making hollowrubber articles vwherein rubber stock is drawn by a vacuum into mold cavities while the edges of' the stock are suitably held across the mouths of the cavities, the coperating parts of the molded stock being thereafter brought into contact and vulcanized. In such operation compressed air maybe entrapped within the article as the parts are brought together.

The object of the present invention is to carrying out such a process. The apparatus -is hereinafter"moreullyl described and its essential characteristics summarized inthe In the drawings, Figure 1 sectionof the apparatus; Figs. 2 and 3 are horizontal vsections `on the lines 2--2 and 3-3 of Fig. 1; Figs. 4 and 5`are views of two sides of the plate for supporting the rubber stock previous to molding, one of a `these viewsibeing. a plan 'and the other a bottom plan. Figs. 2 to 4. are drawn on the same scale, which is smaller than the scale of Fig. 1. Fig. 6 is a vertical section on a larger -scale throughv a lpair of separated mold plates with the material and the supports therefor between .theiplates "ready mentary Viewv on a much larger scale of aportion of one of the supporting-plates with l someofthe rubber stock ,resting thereon;

Ig)A

11 and 12 are details illustrating aclamp- Fig. 8 is a plan of` one of the'lower platen;v

Fig. 9 is a view in-,verticalsection illustrat- Aing two of the coacting mold cavitiesafterv' which may be employed for holding the two mold plates together, showing such clamp respectively inside elevation 'and cross secl tion; Fig. 13 is aside elevation, somewhatv diagrammatic, illustrating the employment' is a vertical' platens.

intermediate vacuum connections, this view being intended as illustrative of any desired number of such molds` and connections.Ik

The apparatus shown in Fig. 1 has a base 1, lupright rods or standards 2 carried thereby, a hea-d 3 secured to the rods near their upper ends, a. casting 4 resting on the base and providing an internal cylinder 5andalso a support for parts above. I have shown suitablenutson the rodsf clamping the base, the casting and the head in place, andthe parts so clamped, together with the rods, constitute the main frame of the machine. V l

10 indicates a tank or receptacle/--sli'dably guided on the rods 2 by means of ears 11 embracing those. rods. This tank is mounted on the upper end of a plunger 12 which extends into the cylinder 5.l A suitable stuffing box 15 embraces-this plunger and is carried by the upper portion of the cylinder. v

16 indicates a pipe leading to the cylinder 5, wherebyv hydraulic pressure may be applied to the lower end -of the plunger to,`

Patented ocal 17, 191e.

l of'aplurality of superimposed molds with sok tionary gasketl 18 lying directly above the I'wall to make an airvtight connection.

20 and Y21 indicate hollow rectangular under face of the head 3` and incidentally carries vnear its outerA 'edge the gasket 18,-;

c above referred to. The platen has onecon- The platen 21V is secured to the tinuous cavity through it, though the under face is preferably vstrengthened by isolated vconl'lecting parts 23.* Numerous ,holes 24 are made through the lower wall or face of -the platen. The platen l21 is of similar construction, having the internal cavity and the holes 25extending upwardly ltherefrom to the face of the platen. The lower platen 21 is supported by a pair of plungers 30 and 4J31, the upper ends of which are secured to :the platen. These plungersextend'` through the bottom ofthe tank 10 into a pair of cylindersi32mounted3n the top of the -casting 5 4.l These plungers are embraced by suitable stu'lng boxes 34 carried by the tank 10- and f other stuling boxes 35 carried by the cylinders 32; A suitable pipe 36 communicates with the two c linders 32,.whereby hydraulic pressure vmay e admitted to raise the` plungers. Admission to the cavity of. the 'lower platen 'is obtained by a tubular-passageway 37 in the lrplunger-30, which passageway is adapted to be in communication with a pipe 38. A pipe '39 leads to the cavity in the platen 20. These pipes 38and 39 provide the means for exhausting' the air from the. platens.v

rlhe mold plates, as illustrated in -a number 'of views, are preferably rectangulark blocks 40 and'41 having several cavities corresponding in contour to the two portions of the article to be molded. The drawings show twenty-five cavities in each mold plate arranged in ive rows of five each, though this number may be varied as desired. An opening 42 is made from each cavity throughA to the opposite face of the .mold plate. These mold plates are preferably clamped against the respective platens on an inter. mediate sheet of rubber 44 and 45 which has holes throughit registering with the holes 42. There are preferably a large number of holes 24 and .25 through the platens, 'some of these holes registering with the holes through lthe rubber plate .and others being' closed by the rubber plates. Accordingly, when the molds' and rubber plates are in place on the platens there isl a. continuous passageway from each cavity to the respective source of vacuum (indicated by the pipes 38 and 39), enabling the air to, be eX- hausted from the variouscavities.

To clamp the lmold 'plates accurately, eecti'velyan'd easily in place on .the platens, I provide each mold plate with an edge rib .50l which is' adapted to lie beneath overihanging langesl secured to the `platen-21 or above corresponding' flanges52 secured` tothe platen 20, :the mold plate being shoved into place from thevfront in Fig.'I 1. When in vthis `position .the plates are eectively clamped byv wedges; driven' between. -thev l flanges.v o n. the platen and the ribs on' the mold lates. Such wedges are'designated 54. T eymay conveniently-have a dove- 4'5. tailed sliding connection with. Vthe platen flanges. a Figs. 4,5, 6 and 7 v,illustrate metal plates" 60 adapted to support'the sheets of rubber 4stock as they are put- .in place between the l `molds. This inetal plate has on one 'face annular 'grooves 61, the diameter of'jwhich corresponds -with the-"diameter` ofthe rubber stock which is preferablyfof disk form. y shown atA. These annular grooves, there-- fore, serve tov enable theaccurate positioning of Vthe stock and they perform another function, hereinafter stated.. Extending "through -the plate within each annular groove is ang 'l *opening'62', andon theunder side of lthe` plate are .groovesl 63 registering withv the openings. After4 the rubber disk has been placed von two of'these plates and-'are held i lthere -by-ftheir vownv adhesion,A tw of the plates are-placed. backto vback and`located-- g55-between the molds, as 'shown' in Fig.

Then, if the molds are. brought together it will be seen thatthe edges of the rubber stock are clamped around the edges of the mold cavities. To bring the mold plates together it is simply necessary tb admit hydraulic pressure to the pipe 36, which acts upwardly on the plungers 30.l and 31, raising the lower mold plate. When the parts are in this position a vacuum applied to the pipes 38 land-39 will exhaust air from the mold cavities, wherefore the rubber' stock is drawn into the cavities, as shown in Fig. 9. In thisvmovement, atmospheric. air is admitted between the vrubber stock and the supporting plate (lO-through the grooves 63 and openings. 62 described.

Thespecific shape of'the`mold cavities .shown is designed for manufacturing atomizer bulbs of the final form shown in Fig.

10. Thev raw. rubber stock for each half preferably consists of a disk A and a smaller part of rubber algasl shown 'in Figs. 6 and 7.

When such stock is .drawn into the mold cavity'shown, it produces the generalshape vindicated lat B, the small rubber disk a pro- `viding for the thickened boss b of the .molded article, whichV may be afterward drilled lto produce the tubular opening shown at c in Fig. 10. The annular groove 61 referred-to-in the supporting plate, to-

. gether with the rounded edge 65 of the mold cavity: produces a' rounded bead 7J at vthe edge of the `molded section.` 'When the halves of the article have been molded as described, they are adapted to be brought together to l complete the closed article. Preceding such bringing together the mold plates are separated by releasing" the hydraulic pressure inthe pipe 36, and the stripped plates 60 are removed. lt may be desirable .to obtain aninternal pressure in excess ofiatmospheric pressure within the cavities of the articles, as they areebrought together,1an'd itc-is toaccbm lish this that l provide thetank 10 hereto ore mentioned,

.the operation of which 'will now be der scribed.

After the mold plates carrying their half sections have been separated (being thus in the position shown in Fig; 1)v hydraulic pressure is admitted through the pipe 16 tothe cylinder', which, acting upwardly on the plunger I2, raisesthe tank -10 into the plugers 30. and 31 being carried upward by lfriction in thism'ovement,.l provide a ysuitable catch, as', for example, the' plunger y31. Aftervthe upper edge of the j engagement lwith `.they gasket 18.l To prevent wall 10` has come into contact with' vthe gasket '18, .the valveis openedin a--pipe 70,

which may be connected with, a suitable supj ply of ycompressed air, and compressed air ls thus admittedtoithe' rir of the tank" mold plates are .to be removed 'for with the space within the vessel 10 'and thus vas consisting two plates may be removedrtofany conthis compressed air surrounding the mold and passing into the interiorof thev cavities. Thenthe latch '73 is turnedvback a'ndhydraulic pressure admitted to the cylinders 32, thus bringing the mold plates together which present the edges of the articles to each other to cause them to adhere, entrapping compressed air within the closed articles. The desired operation of the two sets of plungers is easily obtained by turning the handles on two valves orv cocks 75 and 76 on the pipes 15 and 16, each valve having a position when -it 'admits fluid under pressure to the cylinder, a second position when it holds such fluid entrapped, and a third position when it vents the cylinder. A pressure gage 78 is' in communication enables an exact and desired amount of' pressure to be attained within the interior of thev closed article. The closed article. is

vulcanized with this pressure within it, and while the article Within the mold. After vulcanization and the removal of the article, if it is to constitute 1an, open bulb, for example, an opening into it releasesl the pressure. The bulb C shown in Fig. 10`, has two drilled openings c." This figure shows the vulcanized circular `joint c. The vul-v canization may be accomplished within the press shown, orat some other point. .If the vulcanization, the operation is as follows: The air is relieved from thetank 10, a vent -pipe 8O providing for this, and the pressure isrelieved in the cylinder' 5., causing the tank. todescend.' Then suitable clamps are driven on the mold to hold them together. These clampsare shown in Figs; ll-and 12 of a yU-shavped member 82 having internal wedge faces which coact with wedge-shaped lugs 83 on the mold plates. When these keepers are -driven inv place the venient vu'lcanizer. v v

ShouldA it be desirable* to vulcanize the articles while in the.press,'theair pressure is relieved' through-the vent ,'80 and steam is admitted tothe interio'rvofJ the vessel 10. This steam mayenter through the same pipe 7 0, ifi-desired. Also, ifdesired,`steam4 may*V be "admitted throughV the pipes 38 and 39 into-the spaces provided V'for vacuum, as above described. Y Circulation of this steam maybe provided by opening the normally closedvent from thechamber 10,' a .nor-1 mally closed vent 85'from the cavity of the platen .20, and a normally closed vent 86 lconnected with the, cavity of the platen 21 by a passageway 87 in the plunger 31. After the steam vulcani'zation is completed, the

, parts may be cooled by the admission of water through the same'pipes, the vents described allowing the escape of the water.-

-, 65 The apparatus described is shown Fig.

the platens.

vacuum. This is illustrated in .Fig. 13,v

where two pairs of mold plates are shown with an intermediate hollow platen l90 befrom it,and it has an external connection 93 'with the source of vacuum. Suitable rubber plates 94; and 95 similar to the plates 44 and 4:5 are placed onvopposit'e sides of this platen and coact with the molds above .and below the platen. Any suitable means Y may be employed for supporting the interby it whenl the parts are separated.

' Having thus described my inventlon what I claim is:

vtween them. This platen has openings 91 y yand 92'leading vupwardly anddownwardly 75 l mediate platen and the moldplates carried I f1. In an apparatus ofthe character def scribed, thecombination with a pair of holtion with the interior 'of the platens, and a tubularconnection with theplatens vwhereby air maybe exhausted from the mold cavities. I l 2. The combination of a hollow platen having `openings .to its face, a mold plate movable independently of the platen and adapted to` rest against said platen-and 'provided with a series of cavities each having .an opening to the oppositeside of the plate, `and means for vholding the plate-.in place on the platen with ,their openings communicatin'g, and means' for` exhausting the air in' the platen.

The combination of a pair of hollow co i i a pai'ryof mold plates in-l f openings whereby thecavities 'ofi-themold-plates may com- Y municate with the cavities of the platens, and means? for lclamping ,the mold against.

operating platens, dependentl of the' platens,

4. The combination with a' holiow pia-een;-

low coperating platensone of which` is movablepof mold plates' separate Vfrom the platens and having cavities in communicaof 'a mold plate-,having a series of cavities,

openings through the cavities to the opposite f l -sidev of the mold plate, a sheet of .rubber or fsimilar material between' the mold plate `and platen, and a lpassageway in communication with the interior of the platen'whereby air may be'exhausted from the cavities.

5. The combination of av hollow fiat platen,

openings from the interior' of the platen to y its face, a mold-platel havinga series vof cavities, openings from-the cavities to they other side `ofthe mold plate, pads having openings and adapted to lie between the mold and platen, means for locking the mold `plate in place on the pad on the platen, and

means for exhausting' the air from the 'platen'. .'6..The combinationofapair of hollow flatplatens facing each other and one of whichv is movable, openings from the interior of keach platen-to its face, tubular passageways communicating respectively with the interior l of the platens, a pair of mold plates each "having a series of cavities, openings from the cavities to the other side of the mold plate, pads having 'openings and adapted to l' -lie between the respective molds and platens, and meansfor locking the mold plates in place on the pads onthe-platens.

7. The combination of a hollow platen, a

. mold plate, openings whereby the cavities of the mold plate may communicate with the cavities of the platen, a rib on theedge'of *ses the mold plate,`1and a wedgeco'actingj with (said'rib for clamping the mold plate against the platen.

` y8. The combination with a hollowA platen,

of a mold plate adaptedto rest thereon havu ing vcavities in communication with the holv low of the platen, a plunger for moving the .l platen, and a tubular opening in said plunger communicating with the interior of the platen. r u

9. rlhe combination of a press having 4a head, a hollow downwardly facing platen carried byy said head, amovable upwardly facing hollow platen, mold plateseach hav- `ing a series of cavities adapted to bemounted fee below and above the respective platens and have their cavities in communicationwith .the cavities of the platens, a. plunger for raising ythe lower platen, and means for exhaustingl thel air' the interior of .the

platens.. v I- 10, Thefbcombination ofvka press having a head, a hollow 'downwardly facing platen carried by said fhead, a movable upwardly' facing hollovv platen, coperatin'g.. mold plates each' having 4a series of cavities and adapted tov be positioned between 'the re# f spective -platens and have their cavities in communication with the cavities of the;

platens, means 'forsupporting the upper mold plate in coactlfon with the upper platen,

a plungerforraising 1 the lower platen, a

tubular passagewayin said plunger-leading to theyinterior of the lowerplaten,and a l .tubular passagewaytleading tothe interior 'oftheupper-'platen 1I. The comb'nation with aninclosing de- .hausted from; Saidlplatens, `and.- means for 'f'adjgnittin'g fluidl under pressure tothe f'ported head, vlof apair of mold plates,Av one of which isisuspe'n'ded on the under face of.'

the. head, a movable receptacle belowfthe head 'having ajcl'osed bottom and a` wall,

means for raising said receptacle to close the space betweenit and the head, and means forsupportingthe lower mold lsection within the chamber thus provided.

13. The combination of a suitably sup-A ported head, means for suspending a downwardly facing mold on the under face of the head, a platform beneath the head, the lower member of the mold being adapted to rest on said platform', a movable receptacle extending beneath the platform-andl having a wall adapted to lie outside of it, said wall being adaptedto stand a distance below the head, a' plunger adapted to raise said receptacle to-close the space between it and the head, and means for'supp'lying fluid under pressure to the chamber thus provided.

14:. The combination ofa suitably supported head, means for suspending a downwardly facing mold on the under face of the head, a platform beneath the head, the lower member ofthe mo'ld being adapted to rest on said platform, means for exhausting the air from the cavities of the mold, a movable receptacle extending beneath theplatform and having a wall adapted to lieoutside of it, said wall being adapted to stand a distance below the head, a plunger adaptedto raise said receptacle, a gasket supported `by the head for making a tight' connection with said wall when raised, and means for supplying fluid under ber thus provided. .,15.-"li`he combination of a pair-"of mold plates, ahead and a movable platen between which the plates stand, a plunger for mov'- pressure to the cham-y ing said platen, means adapted to ,inclose fthe plates including a movable receptacle adapted toco-actwith the head,'sai dl plunger extending movably through the receptacle, means lfor exhausting air from s aidr platen and vmeansfor moving the receptacle.

16. vThe combination of a stationary head,

of 'a-movablereceptacle, the wall of whichy is adapted to coactv with the head or be spacedtherefrom, a plunger for moving said .Teceptacla a hollow platen carried on llt'he ,face of the head'toward the receptacle, a

movablehollow platen within the receptacle,

.. means for-exhausting ail-'from Vsaid platens,

anda plunger extending throughl the base of the .receptacle for'fmovillg `the vmovable platen. 'f v v llllll `17. The combination of a head, a movable l receptacle, the wall ofwhich is adapted to coact with' the head or be spaced therefrom, a-.plunger for moving` said-receptacle, 'a

platen carriedon the face of the head to Y ward the receptacle, a movable platen with .in the receptacle', a plunger.' extending through 'the base of the receptacle for moving'said movable platen, said platens being hollow, and means Communicating with the a interior thereof whereby *he air may be exhausted therefrom.

4 wall being adapted to coact with the head or stand spaced from it, a plunger for so',

moving the receptacle, a platen within the receptacle through lthe base vof the receptacle, a codevice having toward the receptacle,

' an upwardly acting platen carried on the face of the head the plunger connected with the platen to hold the same against movement resulting from 'friction with the receptacle.

19. The combination with an inclosing to engage tacle, of a pair of'hollow platensadapted to be inclosed by said device, means whereby air may be exhausted from said platens, means for admitting fluid under pressure to the inclosure, means for moving the r'eceptacle, and a plunger connected with one -of the platens `and movably extending through the receptacle.

'- Q0. In a device of the character described,

the combination of a base,'standards rising therefrom, a head carried by said standards.`

head, a plunger for said receptacle, a movable hollow platen within vthe receptacle, means for exhausting air from said platen and a' plunger for moving it passing through the base of the receptacle. i

21. The combination with a base, of standards rising therefrom, a stationary head carried by the' standards, a movable` upwardly facing vreceptacle guided by said having a plunger extending and a catch adapteda head and a movable recep-l facing receptacle below' the" supporting plates cylinders supported above the cylinder first mentioned, upright standards rising from the base, a movable receptacle consisting of a base and wall, a plunger connected with the base and occupying the -main cylinder, a platen within the receptacle, a plurality of plungers depending from the platen passing through the base of the receptacle and occupying the 'upper cylinders, a head carried by said standards, and an upper platen secured on the under face of lthe head. 4

24. rI`he combination with a pair of mold plates, of a supporting plate adapted to be placed rated and carry the stock for molding, said supporting plate having a series of annular grooves in one face, and openings through the plate from the spaces within the grooves.

25. The combination with a pair of separabl'e mold plates, of a supporting plate having on one face a1 series of annular grooves, openings through the plate, and in the other face grooves communicating with the openings and leading to an edge of the plate.

26. rable mold plates having facing` cavities, a pair' of supporting plates adapted to be placed between the mold plates and carry stock o'n theirupper and under faces,A said ting air to the spaces between them and the stock, and 'means enabling the exhaustion of airfrom the cavities of the molds.

"27. The combination with' a pair of sepastand-ards, a central plunger on theunder. rable-mold plates having facing cavities, a

side lof the receptacle for shoving itupwardly, rality of plungers depending from the' platen passing 23. The combination of a base, a main cylinder mounted thereon, a Vplurality of a platen within the receptacle, a pluthrough the base of the receptacle) and spaced about the plunger first men-l pair ofv supporting plates adapted to be between the mold plates when sepa- The combination with a pairof sepahaving means for admit.

placed between the'mold plates and carry stock on their upper land under faces, said supporting plates having means for admit ting air to the Spaces between them and the stock, a' pair of hollow platens against which the molds, may rest, the cavities'of the molds being in communication with the cavities of the platens, and passageways to the platens whereby the air may be exhausted from the cavities after the mold brought together upon the A l osed stockA and supporting plates.

plates interp Inetestimony whereof, I hereunto 'aix have been vmy signature.

FRED THOMAS ROBERTS.

Witness: l

HERBERT R. Smnss. 

